1 files changed, 57 insertions, 0 deletions
diff --git a/vendor/github.com/wybiral/torgo/ed25519.go b/vendor/github.com/wybiral/torgo/ed25519.go
new file mode 100644
index 0000000..bbdd0c7
--- /dev/null
+++ b/vendor/github.com/wybiral/torgo/ed25519.go
@@ -0,0 +1,57 @@
+package torgo
+
+import (
+	"crypto/sha512"
+	"encoding/base32"
+	"encoding/base64"
+	"errors"
+	"strings"
+
+	"golang.org/x/crypto/ed25519"
+	"golang.org/x/crypto/sha3"
+)
+
+// OnionFromEd25519 returns an Onion instance from an ED25519 private key which
+// can be used to start a hidden service with controller.AddOnion.
+func OnionFromEd25519(pri ed25519.PrivateKey) (*Onion, error) {
+	pub, ok := pri.Public().(ed25519.PublicKey)
+	if !ok {
+		return nil, errors.New("torgo: unable to extract ed25519.PublicKey")
+	}
+	serviceID, err := ServiceIDFromEd25519(pub)
+	if err != nil {
+		return nil, err
+	}
+	h := sha512.Sum512(pri[:32])
+	// Set bits so that h[:32] is private scalar "a"
+	h[0] &= 248
+	h[31] &= 127
+	h[31] |= 64
+	// Since h[32:] is RH, h is now (a || RH)
+	key := base64.StdEncoding.EncodeToString(h[:])
+	return &Onion{
+		Ports:          make(map[int]string),
+		ServiceID:      serviceID,
+		PrivateKey:     key,
+		PrivateKeyType: "ED25519-V3",
+	}, nil
+}
+
+// ServiceIDFromEd25519 calculates a Tor service ID from an ed25519.PublicKey.
+func ServiceIDFromEd25519(pub ed25519.PublicKey) (string, error) {
+	checkdigits := ed25519Checkdigits(pub)
+	combined := pub[:]
+	combined = append(combined, checkdigits...)
+	combined = append(combined, 0x03)
+	serviceID := base32.StdEncoding.EncodeToString(combined)
+	return strings.ToLower(serviceID), nil
+}
+
+// ed25519Checkdigits calculates tje check digits used to create service ID.
+func ed25519Checkdigits(pub ed25519.PublicKey) []byte {
+	checkstr := []byte(".onion checksum")
+	checkstr = append(checkstr, pub...)
+	checkstr = append(checkstr, 0x03)
+	checksum := sha3.Sum256(checkstr)
+	return checksum[:2]
+}